Land grid array socket having improved terminals

ABSTRACT

A land grid array socket ( 1 ) in accordance with the present invention is provided. The socket comprises an insulative housing ( 2 ) having a plurality of passageways ( 24 ) extending throughout an upper mating surface ( 22 ) and a lower mounting surface ( 20 ). A plurality of electrical terminals ( 3 ) are received in corresponding passageways, each terminal comprises a first part ( 32 ) having a first spring arm ( 322 ) extending out of the upper mating surface for electrically connected to an IC chip ( 4 ) and a second spring arm ( 306 ) extending out of the lower mounting surface for electrically connected to a motherboard ( 5 ). The first part and the second part are accommodated in a same passageway and separate from each other while interconnected by a third spring arm ( 304 ) settled therebetween.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the art of electrical connectors, andmore particularly to a land grid array (LGA) socket having electricalterminals for electrically connecting two separate electroniccomponents.

2. The Prior Art

A conventional land grid array (LGA) socket 6 is illustrated in FIGS.6-7, the socket 6 basically comprises an insulative housing 60 having aplurality of passageways formed therein, each passageway receives anelectrical terminal 62 therein. The terminal 62 includes a base portionfor securing the terminal 62 in the passageway and a pair of spring arms622 and 624 respectively extending out of opposite surfaces of thehousing 60 and resisting two separate electronic components 7 and 8 soas to establishing electrical connection between the two components 7and 8.

Referring to FIG. 7, while the electronic components 7 and 8 are down totheir final position, a height H between the components 7 and 8 arenormally unchangeable in order to maintain a sufficient pressing forcebetween the spring arms 622 and 624 as desired by establishingsuccessfully electrical connection. However, under some particulardesign consideration, there is a need to increase the height H.Consequently, the base portion 620 of the terminal 62 has to beelongated such that the whole length of the terminal 6 can satisfy therequirement of the increased height H. As a result, the die formanufacture of the terminal 62 has to be modified to make a differentconfiguration, which increases the overall cost of the LGA socket 6 andmakes the manufacture process of the LGA socket become relativelycomplicated.

Further, the LGA socket is often used to transmit high frequencysignals, which requires the terminals used in the socket have arelatively high capacitance and a relatively low impedance. However, theterminal 62 as disclosed in FIGS. 6 and 7 has a very simpleconfiguration and its low capacitance and high impedance cannot fulfillthe requirement of high frequency signal transmission. Therefore, thereis a need to invent an improved terminal to resolve the above-mentionedshortcomings.

SUMMARY OF THE INVENTION

Accordingly, a main object of the present invention is to provide anland grid array (LGA) socket having an improved terminals, wherein theterminals simplify manufacture of the LGA socket and ensure desired highfrequency signal transmission.

To fulfill the above-mentioned object, a land grid array socket inaccordance with the present invention is provided. The socket comprisesan insulative housing having a plurality of passageways extendingthroughout an upper mating surface and a lower mounting surface. Aplurality of electrical terminals are received in correspondingpassageways, each terminal comprises a first part having a first springarm extending out of the upper mating surface for electrically connectedto an IC chip and a second spring arm extending out of the lowermounting surface for electrically connected to a motherboard. The firstpart and the second part are accommodated in a same passageway andseparate from each other while interconnected by a third spring armsettled therebetween. According to one embedment of the presentinvention, the third spring arm functions as a bridge portion andextends from a second base portion of the second portion toward a firstbase portion of the first part and resists a main plane of the firstbase portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an perspective view of an electrical terminal of a land gridarray (LGA) socket in accordance with a first embodiment of the presentinvention.

FIG. 2 is a cross-sectional view showing the terminal of FIG. 1 beingreceived in an insulative housing of the LGA socket, before an IC chipand a mother board establish electrical connection with the terminals.

FIG. 3 is similar to FIG. 2, showing the state after the IC chip and themother board establish electrical connection with the terminals.

FIG. 4 is an perspective view of an electrical terminal in accordancewith a second embodiment of the present invention.

FIG. 5 is an perspective view of an electrical terminal in accordancewith a third embodiment of the present invention.

FIG. 6 is an perspective view of a conventional LGA terminal.

FIG. 7 is an cross-sectional view of a conventional LGA socket.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Reference will now be made to the drawings to describe the presentinvention in detail.

Referring to FIGS.1 and 2, a land grid array (LGA) socket 1 inaccordance with a first embodiment of the present invention isillustrated. The socket 1 comprises an insulative housing 1 having aplurality of passageways 24 formed therein, each passageway 24 extendsthroughout a mating surface 22 and a mounting surface 20 of the housing2 and accommodates an electrical terminal 3 therein. The terminal 3 hassprings arm respectively extending out of the mating surface 22 and themounting surface 20 for electrically connecting with a first electroniccomponent above the mating surface 22 and a second electronic componentunder the mounting surface 20. In this embodiment, the spring armsrespectively connect with contacting pads 40 of an IC chip 4 and contactpads 50 of a motherboard 5.

Referring to FIG. 1, the terminal 3 comprises a first part 32 and asecond part 30, the two parts 32 and 30 are separate from each other.The first part 32 comprises a first base portion 320 which has a planarmain plane 3202 and a pair shoulders 3200 for securing into a slot in aninner wall of the passageway 24. A first spring arm 322 extends outupwardly from one upper end of the base portion 320, and the firstspring arm 322 forms a first contacting end 3220 in a free end thereofwhich resists the contacting pad 40 of the IC chip 4 when the terminal 3is received in the passageway 24. The second part 30 comprises a secondbase portion which includes a end wall 300 and a side wall 302vertically bending from one side of the end wall 300. A second springarm 306 extends out downwardly from one lower end of the end wall 300,and the second spring arm 306 forms a second contacting end 3060 in afree end thereof which resists the contacting pad 50 of the motherboard5 when the terminal 3 is received in the passageway 24. A third spring304, functioning as a bridge portion, extends out from one side of theside wall 302 and forms a third contact end 3040 which resists the mainplane 3202 of the first base portion 320 when the terminal 3 is receivedin the passageway 24. Thus, electrical connection between the first part32 and the second part 30 of the terminal 3 is established via thebridge portion 304 settled therebetween.

Referring to FIG. 3, when the IC chip 4 and the motherboard 5 all pressdown to its final electrical connecting position and contact with thespring arms 322 and 306, a vertical height between the two spring arms322 and 306 is determined. Because of relatively simple structure of thefirst part 32, it is easy to downwardly insert the base portion 320 ofthe first portion 32 to a deeper position in the passageway 24 along theslot in the inner wall of the passageway 24, or upwardly pull the baseportion 320 of the first portion 32 out of the passageway 24 to ashallower position in the inner wall of the passageway 24 along theslot. Thus, desired modification of the vertical height is easilyreached without any design change on the terminal 3 and the housing 2,which will greatly decrease the whole manufacturing cost of the socket1.

Referring to FIG. 4, an electrical terminal 3′ in accordance with asecond embodiment is illustrated, a second part 30′ of the terminal 3′comprises a end wall 300′ and a pair of side walls 302′ verticallybending from opposite sides of the end wall 300′, respectively. Thus,when the terminal 3′ is received in the passageway 24 of the housing 2,the end wall 300′, the side walls 302′ and the first base portion 320′of the first part 32′ surround a substantially encircled inner space.The settling of the inner space increases the capacitance of theterminal 3′ as well as decreasing the impedance of the terminal 3, whichgreatly benefits high frequency signal transmission.

Two preferred embodiments in accordance with the present invention havebeen shown and described. However, in another alternative embodiment asshown in FIG. 5, a vertical length H″ of the second base portion 30″ ofthe terminal 3″ is longer than a vertical length H′ of the second baseportion 30′ of the terminal 3′, this kind of modification can alsomodify the high frequency characteristic of the terminal to its desiredlevel. Further, in another alternative embodiment, the third spring armcan also be set on the first base portion of the first part or otherplace in the passageway, if only it can function as a bridge portion tointerconnect the first and second parts of the terminal. Therefore,equivalent modifications and changes known to persons skilled in the artaccording to the spirit of the present invention are considered withinthe scope of the present invention as defined in the appended claims.

1. an electrical connector, comprising: an insulative housing having amating surface adapted to mate with a first electronic component and anopposite mounting surface adapted to be mounted on a second electroniccomponent, the housing including a plurality of passageways throughoutthe mating surface and the mounting surface; a plurality of electricalterminals received in the insulative housing; each terminal including afirst part having a first spring arm extending out of the mating surfacefor electrically connected to the first electronic component and asecond part having a second spring arm extending out of the mountingsurface for electrically connected to the second electronic component,and the first part and the second part being accommodated in a samepassageway and separate from each other but interconnected in the samepassageway by a bridge portion formed on one of the first and the secondparts.
 2. The electrical connector of claim 1, wherein the first partcomprises a first base portion, the first spring arm extending out ofthe mating surface from one end of the first base portion.
 3. Theelectrical connector of claim 2, wherein the second part comprises asecond base portion, the second spring arm extending out of the mountingsurface from one end of the second base portion.
 4. The electricalconnector of claim 3, wherein the second base portion comprises an endwall opposite to the first base portion and a side wall bendingvertically from one side of the end wall.
 5. The electrical connector ofclaim 4, wherein the second spring arm extends out of the mountingsurface from one end of the end wall.
 6. The electrical connector ofclaim 4, wherein the bridge portion comprises a third spring armextending from one side of the side wall toward the first base portionand resisting a main plane of the first base portion.
 7. The electricalconnector of claim 3, wherein the second base portion comprises an endwall opposite to the first base portion and two side walls bendingvertically from opposite sides of the end wall, respectively.
 8. Theelectrical connector of claim 7, wherein the end wall and side walls ofthe second base portion and the first base portion forms a substantiallyencircled inner space.
 9. The electrical connector of claim 4, whereinthe bridge portion comprises a third spring arm extending from the firstbase portion toward the second base portion and resisting the secondbase portion.
 10. A land grid array (LGA) socket adapted to electricallyconnect an IC chip and a mother board, the socket comprising: aninsulative housing having a mating surface for mate with the IC chip andan opposite mounting surface for mounting on the mother board, thehousing including a plurality of passageways throughout the matingsurface and the mounting surface; a plurality of electrical terminalreceived in corresponding passageways, respectively; each terminalincluding a first part having a first spring arm extending out of themating surface for electrically connected to the IC chip and a secondpart having a second spring arm extending out of the mounting surfacefor electrically connected to the mother board, the second part beingseparated from the first part and contacting with the first part via athird spring arm formed therebetween, and the first part being movablewith respect to the second part so as to adjust a whole height of theterminal.
 11. The socket of claim 10, wherein the first part comprises afirst base portion, the first spring arm extending out of the matingsurface from one end of the first base portion.
 12. The socket of claim11, wherein the second part comprises a second base portion, the secondspring arm extending out of the mounting surface from one end of thesecond base portion.
 13. The socket of claim 12, wherein the second baseportion comprises an end wall opposite to the first base portion and aside wall bending vertically from one side of the end wall.
 14. Thesocket of claim 13, wherein the third spring arm extends from the bottomof the end wall toward a main plane of the first base portion andresisting the main plane.
 15. The socket of claim 10, wherein said thirdspring arm integrally extends from one of said first part and saidsecond part to engage the other.
 16. An electrical connector,comprising: an insulative housing having a mating surface adapted tomate with a first electronic component and an opposite mounting surfaceadapted to be mounted on a second electronic component, the housingincluding a plurality of passageways throughout the mating surface andthe mounting surface; a plurality of electrical terminals received incorresponding passageways, respectively; each terminal including a firstpart having a first contact portion extending to the mating surface forelectrically connected to the first electronic component and a secondpart separated from the first part and having a second contact portionextending toward the mounting surface for electrically connected to thesecond electronic component; an wherein the first part is electricallyconnected to the second part via a connecting portion formedtherebetween, and the first portion and the second part corporatelyencircle a space so as to increase the capacitance of the terminal whiledecease the impedance of the terminal.
 17. The electrical connector ofclaim 16, wherein the first part comprises a first base portion and thefirst spring arm extends out of the mating surface from the one end ofthe base portion.
 18. The electrical connector of claim 17, wherein thesecond part comprises a second base portion which has a end wall and twoside walls bending vertically from opposite side of the end wall, thespace being formed among the end wall, the side walls and a main planeof the first base portion.